The present invention relates to a press machine wherein a piston for a striker device connected to a freely vertically movable ram on the press machine is caused to move.
Conventionally, in a punch press such as a turret punch press or the like, a material is subjected to a punching process through the collaborative operation of a punch and die by applying a striking force to a punch from a striker device connected to a freely vertically movable ram. The striker is fabricated from a block or a plate, and it is impossible to modify the stroke of the striker or to adjust an open height (or shut height).
With a striker of the above-described conventional structure, the stroke is regulated by the vertical movement of the ram. Accordingly, there is the problem that the movement of the striker cannot exceed the stroke of the ram, and it is not possible to modify the stroke or stop the punch midway by adjusting the open height (or shut height).